Integrated Device Placement and Control Design in Civil Structures Using Genetic Algorithms

One challenge in the application of control systems to civil engineering structures is appropriate integration of a control system into a structure to achieve effective performance. Placement of control devices is strongly linked to the performance of a control system, and the most appropriate device placement scheme is strongly dependent on the performance objectives of the control system. Additionally, for the most effective control system, the placement scheme should be integrated with the design of the controller rather than sequential. This paper proposes an integrated technique to place devices and design controllers based on the use of genetic algorithms. The approach is flexible, allowing the designer to base the placement scheme on performance goals and/or system requirements. Active control devices are used and an H2/LQG controller based on acceleration feedback is selected for this study based on previous successes with this approach in civil engineering systems. To illustrate the proposed methodology, two numerical examples are considered. The first example considers a 40-story shear building, and the second is a full-scale, irregular, nine-story building. Control is achieved through the placement of one or more active control devices placed on various floors in an active bracing configuration. The improvements in the effectiveness of the proposed methodology as compared to previously developed techniques are demonstrated through comparative studies.